The SHA-1 hashing function was designed by the United States National Security Agency (NSA) and its algorithm was first published in 1995. On 23 Feb 2017 Google announced the first practical technique for generating a collision. SHA-1 was deprecated in 2011 due to security weaknesses. However, it is still widely used in the internet.
Move SHA-1 SSL Certificates to the SHA-2 Hashing Algorithm Now. SSLCert.com.hk customers can reissue existing SHA-1 Certificates with SHA-2 free of charge during the validity period of the Certificate.